How can we show information of any shape? For example if i drag rectangle from palette and drop after that i need to show its length and width how it can be achieve?
Once a node is drag-and-dropped, the dropped node will be selected. It is commonplace to have a “ChangedSelection” DiagramEvent listener that updates some HTML to show details about the first selected node. You can find examples of this in the samples and introduction documentation.
Or maybe you want to show the dimensions on the node itself. You could customize the Part.selectionAdornmentTemplate to show the information. GoJS Selection -- Northwoods Software shows one that shows a Button for each selected node, but you could show one or more TextBlocks.